Reproduction steps:
1. Open the attached project “TextureBug“
2. Select the Custom Render Texture “Assets/Texture”
3. Save Project (CTRL+S)
4. Observe the Console Window

Expected results: The project is saved without any errors
Actual results: “Graphics.CopyTexture called with mismatching mip counts“ error is logged in the Console Window

Reproducible with: 2020.3.19f1, 2021.3.20f1, 2022.2.8f1, 2023.1.0b7, 2023.2.0a5

Reproducible on: Windows 11

Note: Issue is reproducible when Custom Render Texture has “Enable Mip Maps” and “Double Buffered” properties enabled, and Anti-aliasing is set to “8 samples”